Optical apparatus

ABSTRACT

There is provided an optical apparatus which has excellent assembly performance, can suppress an increase in cost, and attain a decrease in thickness. The optical apparatus includes a board (1) having a photographing optical system and a mechanical system mounted on its surface. A plurality of opening portions (1a, 1b, 1c) are formed in the board (1). The opening portion (1a) is sealed with a sealing member such as a glass member to allow a light beam to pass and prevent dust and the like from entering the storage space for parts between the board (1) and a shield case (49). The photographing optical system mounted on the board (1) includes a stop unit (30) for adjusting the light amount of an object image guided through the opening portion (1a), and prism-like optical members (G1, G2, G3, G4), each consisting of, e.g., a glass or plastic material and having a sculptured surface as a reflecting surface. Light emerging from the optical member (G4) is received by a solid-state image sensing element (2) mounted on the lower surface of the board (1) through the opening portion (1c).

This is a divisional of co-pending application Ser. No. 08/606,845,filed Feb. 26, 1996.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical apparatus for forming anobject image on a solid-state image sensing element through aphotographing optical member.

2. Description of the Related Art

In general, an optical apparatus using a solid-state image sensingelement includes a zoom lens mechanism to obtain a desired photographingrange.

The arrangement of the zoom lens mechanism of this optical apparatuswill be described with reference to FIG. 27. FIG. 27 is a longitudinalsectional view showing the arrangement of the zoom lens mechanism of theconventional optical apparatus.

As shown in FIG. 27, the optical apparatus includes a plurality of lensgroups constituted by a first lens group 101a, a second lens group 101b,a third lens group 101c, and a fourth lens group 101d. The second andfourth lens groups 101b and 101d are moved along the optical axis withinpredetermined ranges. The second lens group 101b is moved to perform azooming operation. The fourth lens group 101d is moved to perform focusadjustment.

An optical low-pass filter 102 and a solid-state image sensing element103 such as a CCD are sequentially arranged on the optical axis behindthe fourth lens group 101d.

The first lens group 101a, the third lens group 101c, the opticallow-pass filter 102, the solid-state image sensing element 103, and thelike are held in a housing 104.

The second lens group 101b is held in a optical holding member 105. Theoptical holding member 105 is supported to be movable along the opticalaxis on a guide pin 106 and a threaded member 107 which extend parallelalong the optical axis. Each end portion of the guide pin 106 issupported on the housing 104.

The threaded member 107 has a threaded portion to be engaged with theoptical holding member 105. Each end portion of the threaded member 107is rotatably supported on the housing 104. A driving force from astepping motor 110 is transferred to the threaded member 107 through agear group 101. When the threaded member 107 is rotated by the drivingforce from the stepping motor 110, the optical holding member 105 isguided by the guide pin 106 and moved along the optical axis uponrotation of the threaded member 107. By moving the optical holdingmember 105, a zooming operation using the second lens group 101b isperformed. The play between the threaded member 107 and the opticalholding member 105 is removed by a biasing spring 108 and a biasingmember 109.

Similar to the second lens group 101b, the fourth lens group 101d issupported in an optical holding member 116. The optical holding member116 is supported to be movable along the optical axis on a guide pin 117and a threaded member 113 which extend parallel along the optical axis.Each end portion of the guide pin 117 is supported on the housing 104.

The threaded member 113 has a threaded portion to be engaged with theoptical holding member 116. One end portion of the threaded member 113is rotatably supported on the housing 104. The other end portion of thethreaded member 113 is rotatably supported on the housing 104 anddirectly connected to the output shaft of a stepping motor 112. When thethreaded member 113 is rotated by a driving force from the steppingmotor 112, the optical holding member 116 is guided by the guide pin 117and moved along the optical axis upon rotation of the threaded member113. By moving the optical holding member 116, focus adjustment usingthe fourth lens group 101d is performed. The play between the threadedmember 113 and the optical holding member 116 is removed by the biasingspring 108 and the biasing member 109.

The moving positions of the second and fourth lens groups 101b and 101d,i.e., the moving positions of the optical holding members 105 and 116,are detected by position detection means (not shown). The detectionamounts are used to control a zooming operation and a focus adjustingoperation.

A stop 114 is disposed between the second lens group 101b and the thirdlens group 101c. The aperture of the stop 114 is adjusted by a drivingforce from a motor 115. The exposure amount is adjusted by thisadjustment of the aperture of the stop 114.

With the recent advances in semiconductor chips such as memories andmicrocomputers, portable information devices have spread. Efforts havebeen made to further miniaturize such devices and improve theirperformance. Portability is a requirement for such portable informationdevices. Regarding the forms of the devices, a low profile is especiallyrequired.

These portable information devices include an optical apparatus forphotographing an object image, information equipment including thisoptical apparatus, and the like. In order to obtain a low-profileoptical apparatus, the overall thickness of the apparatus including aphotographing optical system (a system constituted by, e.g., the lensgroups, the stop, and the solid-state image sensing element in FIG. 27)and a mechanical system (a system constituted by, e.g., the gears andthe motors which drive the lens groups, the motor which drives the stop,and the like in FIG. 27) must be decreased.

In the conventional optical apparatus, however, the first to fourth lensgroups 101a to 101d, the optical low-pass filter 102, the solid-stateimage sensing element 103, and the like are held in the housing 104, andthe motor 115 for driving the stop 114, the stepping motor 110 fordriving the second lens group 101b, the stepping motor 112 for drivingthe fourth lens group 101d, and the like are held outside the housing104. That is, the housing 104 has a three-dimensionally complicatedshape. For this reason, the cost in manufacturing a housing moldgenerally using a plastic mold increases. In addition, sink marks,warpage, and the like are caused by partial heat shrinkage of thehousing 104, and hence it is difficult to manufacture the housing 104with high dimensional precision. Consequently, it is difficult toperform positioning of each lens group with respect to the solid-stateimage sensing element 103, positioning of each holding member,positioning of each position detection means, and the like with highprecision. A slight relative positional offset caused between a givenlens group and a corresponding position detection means makes itimpossible to accurately detect the moving position of the lens group.

Furthermore, for example, the lens groups may tilt or lenses may swingduring movement of the lens groups. As a result, blurring, fluctuationsor the like of a photographed image may occur.

In the conventional optical apparatus, for example, since the opticalholding member 105 is supported on the guide pin 106 and the threadedmember 107 to be symmetrical about the optical axis, the outer diameterof the housing 104 becomes larger as compared with the outer diameter ofthe second lens group 101b. In addition, the motor 115 for driving thestop 114, the stepping motor 110 for driving the second lens group 101b,the stepping motor 112 for driving the fourth lens group 101d, and thelike are held outside the housing 104. For this reason, it is verydifficult to decrease the dimension in a direction perpendicular to theoptical axis, i.e., the thickness in the direction perpendicular to theoptical axis. That is, it is very difficult to obtain a low-profileapparatus.

Since the motor 115 for adjusting the aperture of the stop 114 isdisposed outside the housing 104, a decrease in the overall thickness ofthe apparatus is interfered with the arrangement of the stop 114.

Since the exposure amount is adjusted by adjusting the aperture of thestop 114, the stop 114 must be positioned with respect to the opticalaxis such that the center of the aperture of the stop 114 coincides withthe optical axis with high precision. For this reason, a verycomplicated operation is required for this positioning operation inmounting the stop 114 in the housing 104.

In addition, an electric circuit board on which drive circuits for theposition detection means must be connected to the position detectionmeans through lead wires or a flexible board. For this reason, mountingof such board and parts requires many steps, resulting in a complicatedassembly operation.

Furthermore, an electric circuit board on which an image sensing elementdrive circuit for driving the solid-state image sensing element includedin the photographing optical system and actuator drive circuits fordriving the motors included in the mechanical system are mounted must beconnected to the solid-state image sensing element and the motor throughlead wires, a flexible board, or the like. Such a mounting methodrequires many steps, resulting in a complicated assembly operation.

Moreover, since the optical holding member 105 included in themechanical system is generally supported to be symmetrical about theoptical axis, the outer size of the housing 104 is large as comparedwith the lens system. Since the motors and the like are disposed outsidethe housing 104, the overall outer size of the apparatus furtherincreases. It is, therefore, very difficult to decrease the dimension ofthe apparatus in the direction perpendicular to the optical axis, i.e.,the thickness in the direction perpendicular to the optical axis.

In addition, since mechanical and electric parts must be mounted invarious directions in assembling the apparatus, a cumbersome assemblyoperation is required, resulting in an increase in cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an optical apparatuswhich can prevent deterioration in image quality caused by inaccuraterelative positioning between movable optical members included in aphotographing optical system and position detection means for themembers, and can decrease the overall thickness of the apparatus.

It is another object of the present invention to provide an opticalapparatus which has good assembly performance, can suppress an increasein cost, and can decrease the thickness.

It is still another object of the present invention to provide anoptical apparatus which prevent a light amount adjustment means and itsdriving means from interfering with a decrease in the overall thicknessof the apparatus.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view showing the arrangement of anoptical apparatus according to the first embodiment of the presentinvention;

FIG. 2 is an exploded perspective view showing the arrangement of a stopunit of the optical apparatus in FIG. 1;

FIG. 3 is a longitudinal sectional view showing the arrangement of anactuator of an optical member G2 of the optical apparatus in FIG. 1;

FIGS. 4A to 4C are sectional views taken along a line B--B in FIG. 3;

FIGS. 5A to 5C are sectional views taken along a line A--A in FIG. 3;

FIG. 6 is a longitudinal sectional view showing another arrangement ofthe actuator of the optical member G2;

FIG. 7 is a longitudinal sectional view showing portions around asolid-state image sensing element of the optical apparatus in FIG. 1;

FIG. 8 is an exploded perspective view showing portions around thesolid-state image sensing element of the optical apparatus in FIG. 1;

FIG. 9 is an exploded perspective view showing portions (on the lowersurface side of the board) around the solid-state image sensing elementof the optical apparatus in FIG. 1;

FIG. 10 is a longitudinal sectional view showing another example of howa glass member for protecting the image sensing surface of thesolid-state image sensing element is mounted;

FIG. 11 is a longitudinal sectional view showing still another exampleof how the glass member for protecting the image sensing surface of thesolid-state image sensing element is mounted;

FIG. 12 is a block diagram showing the arrangement of the opticalapparatus in FIG. 1;

FIG. 13 is a graph showing in-focus characteristics in a focusingoperation;

FIG. 14 is a graph showing zoom tracking curves;

FIG. 15 is a longitudinal sectional view showing the arrangement of theboard of the optical apparatus in FIG. 1;

FIG. 16 is an exploded perspective view partly showing a process in amethod of manufacturing the board of the optical apparatus in FIG. 1;

FIG. 17 is a perspective view showing another board used for the opticalapparatus in FIG. 1;

FIG. 18 is a perspective view showing still another board used for theoptical apparatus in FIG. 1;

FIG. 19 is a perspective view showing still another board used for theoptical apparatus in FIG. 1;

FIG. 20 is a view showing a mounted state of the board in FIG. 19;

FIG. 21 is a perspective view showing still another board used for theoptical apparatus in FIG. 1;

FIG. 22 is a longitudinal sectional view showing the board in FIG. 21;

FIG. 23 is an exploded perspective view showing the arrangement of anoptical apparatus according to the second embodiment of the presentinvention;

FIG. 24 is a longitudinal sectional view showing the arrangement of adrive control unit for the second optical member of the opticalapparatus in FIG. 23;

FIG. 25 is a longitudinal sectional view showing the arrangement of adrive control unit for the aperture blades of the optical apparatus inFIG. 23;

FIG. 26 is a sectional view taken along a line C--C in FIG. 25;

FIG. 27 is a longitudinal sectional view showing the arrangement of anoptical apparatus using the conventional solid-state image sensingelement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below withreference to the accompanying drawings.

(First Embodiment)

FIG. 1 is an exploded perspective view showing the arrangement of anoptical apparatus according to the first embodiment of the presentinvention. FIG. 2 is an exploded perspective view showing thearrangement of a stop unit of the optical apparatus in FIG. 1. FIG. 3 isa longitudinal sectional view showing the arrangement of an actuator ofan optical member G2 of the optical apparatus in FIG. 1. FIGS. 4A to 4Care sectional views taken along a line B--B in FIG. 3. FIGS. 5A to 5Care sectional views taken along a line A--A in FIG. 3. FIG. 6 is alongitudinal sectional view showing another arrangement of the actuatorof the optical member G2. FIG. 7 is a longitudinal sectional viewshowing portions around a solid-state image sensing element of theoptical apparatus in FIG. 1. FIG. 8 is an exploded perspective viewshowing portions around the solid-state image sensing element of theoptical apparatus in FIG. 1. FIG. 9 is an exploded perspective viewshowing portions (on the lower surface side of the board) around thesolid-state image sensing element of the optical apparatus in FIG. 1.FIG. 10 is a longitudinal sectional view showing another example of howa glass member for protecting the image sensing surface of thesolid-state image sensing element is mounted. FIG. 11 is a longitudinalsectional view showing still another example of how the glass member forprotecting the image sensing surface of the solid-state image sensingelement is mounted. FIG. 12 is a block diagram showing the arrangementof the optical apparatus in FIG. 1. FIG. 13 is a graph showing in-focuscharacteristics in a focusing operation. FIG. 14 is a graph showing zoomtracking curves.

As shown in FIG. 1, the optical apparatus includes a board 1 having anupper surface on which a photographing optical system and a mechanicalsystem are mounted. A plurality of opening portions 1a, 1b, and 1c areformed in the board 1. The opening portion 1a is sealed with a sealingmember such as a glass member to allow light beams to pass therethroughand prevent dust and the like from entering a part storage space formedbetween the board 1 and a shield case 49.

The photographing optical system mounted on the board 1 includes a stopunit 30 for adjusting the light amount of an object and guided throughthe opening portion 1a, a plurality of prism-like optical members G1,G2, G3, and G4, each consisting of a glass or plastic material andhaving a sculptured surface as a reflecting surface, and a solid-stateimage sensing element 2 for receiving light emerging from the opticalmember G4 and converting it into an electrical signal.

As shown in FIG. 2, the stop unit 30 has two aperture blades 31 and 32which are point-symmetrical with an optical axis K coinciding with theaxis of the opening portion 1a. The aperture blades 31 and 32 aredesigned to rotate about shafts 33 and 34 respectively arrangedtherefor. The aperture blades 31 and 32 rotate on a plane parallel tothe board 1. The shaft 33 of the aperture blade 31 is rotatably insertedinto a positioning hole 37 formed in the board 1. The shaft 34 of theaperture blade 32 is rotatably inserted into a positioning hole 41 inthe board 1. When the shafts 33 and 34 are respectively inserted intothe positioning holes 37 and 41, the aperture blades 31 and 32 arepositioned such that the central position of the aperture regulated bythe rotation of the aperture blades 31 and 32 coincides with the opticalaxis K. As the aperture blades 31 and 32 rotate, the aperture changes toadjust the light amount. The position of the aperture regulated by therotation of the aperture blades 31 and 32 coincides with the opticalaxis K.

The aperture blades 31 and 32 respectively have permanent magnets 35 and36 each serving as part of an actuator. These permanent magnets 35 and36 are also used as magnetic scales for detecting the positions of theaperture blades 31 and 32. The permanent magnets 35 and 36 aremagnetized such that the magnets are disposed in a directionperpendicular to the rotational direction of the aperture blades 31 and32 and in a direction perpendicular to the board 1.

A coil 38, a yoke 39, and a position sensor 40 are disposed on the board1 to oppose the permanent magnet 35. A coil 42, a yoke 43, and aposition sensor 44 are disposed on the board 1 to oppose the permanentmagnet 36.

As will be described later, the yoke 39 is fitted in a recess portion(not shown) formed in the board 1 to be integrated therewith.

The permanent magnet 35, the coil 38, and the yoke 39 cooperate toconstitute an actuator for driving the aperture blade 31. When a currentis supplied to the coil 38 while a magnetic flux is passing between thepermanent magnet 35 and the yoke 39, this actuator rotates the permanentmagnet 35, i.e., the aperture blade 31, about the shaft 33 owing to theinteraction between the magnetic flux and the current. The positionsensor 40 is constituted by a Hall sensor. This Hall sensor detects achange in the magnetic field of the permanent magnet 35 upon rotation ofthe aperture blade 31. The detection value obtained by the positionsensor 40 is used as a controlled variable for controlling therotational amount of the aperture blade 31 to obtain a predeterminedf-number.

The permanent magnet 36, the coil 42, and the yoke 43 cooperate toconstitute an actuator for driving the aperture blade 32. A portion ofthe coil 42 and the yoke 43 are fitted in a recess portion (not shown)formed in the board 1. Similar to the coil 42, the position sensor 44 isconstituted by a Hall sensor for detecting a change in the magneticfield of the permanent magnet 36 upon rotation of the aperture blade 32.

Note that the permanent magnets 35 and 36 may be constituted by plasticmagnets, and the plastic magnets may be integrally formed as portions ofthe aperture blades 31 and 32.

The optical members G1, G2, G3, and G4 have the same function as that ofa lens group formed by combining a plurality of spherical lenses suchthat, for example, light incident through the opening portion 1a and thestop unit 30 is reflected a plurality of number of times within theoptical member G1 and guided into the optical member G2.

The optical member G1 is fixed on the board 1. The optical member G1 hasa pair of shafts G1a for positioning with respect to the board 1. Byfitting the shafts G1a in the corresponding opening portions 1b of theboard 1, the optical member G1 is positioned/fixed on the board 1. Inthis embodiment, the optical member G1 is positioned/fixed on the board1 by fitting the shafts G1a in the corresponding opening portions 1b.However, the optical member G1 may be positioned first with respect tothe board 1 by a positioning means (not shown), and the board 1 and theoptical member G1 may be then fixed to each other with an adhesive.

The optical members G2 and G3 are optical members which are movedparallel to the upper surface of the board 1 in a predetermineddirection (the longitudinal direction of the board 1) to perform azooming (focal length adjustment) operation and a focusing (focusadjustment) operation.

The optical member G2 is fixed to a moving base 3 with an adhesive. Themoving base 3 is made of a high-permeability material such as iron in aflat form. A portion of an actuator for moving the moving base 3parallel to the board 1 in a predetermined direction, a positiondetection unit for detecting the moving direction of the moving base 3,and a position regulation unit for guiding the moving direction of themoving base 3 and regulating its moving position are disposed on themoving base 3.

In this embodiment, as shown in FIGS. 1 and 3 to 5C, a permanent magnet5 as a portion of the actuator, a magnetic scale 7 as the positiondetection unit, and a groove portion 9 having a V-shaped cross-sectionwithin a plane perpendicular to the moving direction of the moving base3 and a groove portion 11 in the form of a recess, which constitute theposition regulation unit, are disposed on the moving base 3. Thepermanent magnet 5 is constituted by two pairs of magnets magnetized ina direction perpendicular to the moving direction of the optical memberG2. Each magnet is disposed in a direction parallel to the board 1.

A coil 17 and a yoke 19, which constitute an actuator together with themoving base 3 and the permanent magnet 5, are disposed on the board 1.As shown in FIG. 3, a portion of the coil and the yoke 19 are fitted ina recess portion 1e formed in the board 1.

A magnetic force from the magnetic scale 7 is detected by a positionsensor 21 constituted by an MR sensor or a Hall sensor. This positionsensor 21 is disposed on the board 1 to oppose the magnetic scale 7.

Rail portions 13 and 14 for guiding the moving direction of the movingbase 3 and regulating its moving position are disposed at positions onthe board 1 to oppose the groove portions 9 and 11, respectively.Grooves each having a V-shaped cross-section within a planeperpendicular to the moving direction of the moving base 3 are formed inthe rail portions 13 and 14. Balls 46 are inserted between the grooveportions 9 and 11 and the corresponding rail portions 13 and 14.

In the actuator constituted by the moving base 3, the permanent magnet5, the coil 17, and the yoke 19, when a current is supplied to the coil17, a driving force is generated owing to the interaction between amagnetic circuit (to be described later) and the current, and the movingbase 3, i.e., the optical member G2, is moved along the optical axis (ina direction perpendicular to the drawing surface in FIG. 3) by thisdriving force. More specifically, as shown in FIG. 5B, the magnetic pathindicated by the dotted line is formed between the permanent magnet 5,the moving base 3 having a permeability, and the yoke 19. When a currentis supplied to the coil 17 in the magnetic path between the permanentmagnet 5 and the yoke 19, the moving base 3, i.e., the optical memberG2, is moved in the direction indicated by the arrow in FIG. 5B by adriving force generated by the interaction between the magnetic forceand the current. By changing the flowing direction of the current, themoving direction of the moving base 3 is changed. For example, themoving base 3 can be moved from the position indicated in FIG. 5B to theposition indicated in FIG. 5A and to the position indicated in FIG. 5C.

While the moving base 3 is moving, an attracting force based on themagnetic force is acting between the permanent magnet 5 and the yoke 19.The moving base 3 and the balls 46 are therefore in tight contactwithout any backlash. When the moving base 3 moves in the directionindicated in FIG. 4A, the balls 46 rotate clockwise. When the movingbase 3 moves in the direction indicated in FIG. 4C, the balls 46 rotatecounterclockwise. During this movement, the posture of the moving base 3is stably held with respect to the rail portion 13 through the balls 46.In addition, since the balls 46 rotate while the moving base 3 ismoving, the rolling friction acting on the contact surfaces between theballs 46 and the moving base 3 and the rail portion 13 is negligiblysmall as compared with the sliding friction acting on the contactportions between the guide pins and the lens holding members in theprior art. The load based on friction during movement of the opticalmember G2 can be reduced. As the moving base 3 moves, the magnetic fieldof the magnetic scale 7 changes. This change is read by the positionsensor 21. The detection value from the position sensor 21 is used tocontrol the movement of the moving base 3.

Although this embodiment uses the permanent magnet 5 constituted by twopair of magnets arranged in the direction parallel to the board 1,permanent magnets 51 and 52, each magnetized in a directionperpendicular to the optical axis, may be used, and these permanentmagnets 51 and 52 may be fixed to a back yoke 53, as shown in FIG. 6.With this arrangement, a magnetic path concentrates in the smallestspatial gaps between the lower surfaces of the permanent magnets 51 and52 and the yoke 19, thereby stabilizing the driving force and themagnetic path.

Similarly, the optical member G3 is fixed to a moving base 4 with anadhesive. The moving base 4 has the same arrangement as that of themoving base 3. A permanent magnet 6 as a portion of an actuator, amagnetic scale 8 as a position detection unit, and a groove portion 10having a V-shaped cross-section within a plane perpendicular to themoving direction of the moving base 4 and a groove portion 12 in theform of a recess, which constitute a position regulation unit, aredisposed on the moving base 4.

A coil 18 and A yoke 20 which constitute an actuator together with themoving base 4 and the permanent magnet 6 are disposed on the board 1. Aswill be described later, the yoke 20 is constituted by an iron basewhich is fitted in an opening portion (not shown) formed in the board 1to be integrated with the board 1.

The actuator constituted by the moving base 4, the permanent magnet 6,the coil 18, and the yoke 20 performs the same operation as thatperformed by the actuator constituted by the permanent magnet 5, thecoil 17, and the yoke 19.

The magnetic force of the groove portion 9 is detected by a positionsensor 22 constituted by an MR sensor, a Hall sensor, or the like. Thisposition sensor 22 is disposed on the board 1 to oppose the grooveportion 9.

Rail portions 15 and 16 for guiding the moving direction of the movingbase 4 and regulating its moving position are disposed at positions onthe board 1 to oppose the groove portions 10 and 12, respectively.Grooves each having a V-shaped cross-section within a planeperpendicular to the moving direction of the moving base 4 are formed inthe rail portions 15 and 16. Balls 47 are inserted between the grooveportions 10 and 20 and the corresponding rail portions 15 and 16. As themoving base 4 moves, the optical member G3 moves in a predetermineddirection. The frictional forces generated between the groove portions10 and 12 and the corresponding rail portions 15 and 16 during movementof the moving base 4 are reduced owing to the rolling movement of theballs 47.

In this embodiment, the optical members G2 and G3 and the moving bases 3and 4 are fixed to each other with an adhesive. However, the opticalmembers G2 and G3 may be formed by insert molding or outsert moldingwith respect to the moving bases 3 and 4 such that the optical membersG2 and G3 are integrally formed with the moving bases 3 and 4.

The optical member G4 is fixed to the board 1 with an adhesive. Theoptical member G4 is disposed on the board 1 such that the optical axisof light emerging from the member coincides with the axis of the openingportion 1c of the board 1. An optical filter (not shown) for removingunnecessary high-frequency components and infrared rays contained in anobject image is bonded to the optical member G4. Note that this opticalfilter may be integrally formed with the optical member G4 bydeposition.

In the optical system constituted by the optical members G1, G2, G3, andG4, light incident through the opening portion 1a of the board 1 and thestop unit 30 is reflected by the optical member G1 in a directionparallel to the upper surface of the board 1, the reflected light isguided to the optical member G4 by the optical members G2 and G3, andthe light then emerges from the optical member G4 in a directionperpendicular to the upper surface of the board 1.

The light emerging from the optical member G4 is guided to thesolid-state image sensing element 2 through the opening portion 1c ofthe board 1.

As shown in FIGS. 1 and 7 to 9, the solid-state image sensing element 2is mounted on the lower surface of the board 1. As shown in FIG. 8, thesolid-state image sensing element 2 has a plurality of terminals 904including an terminal for outputting accumulated signals and a terminalfor receiving timing pulses and the like. The terminals 904 are disposedon the image sensing surface 905 side of the solid-state image sensingelement 2. The solid-state image sensing element 2 is disposed on thelower surface side of the board 1 such that the optical axis of theimage sensing surface 905 coincides with the axis of the opening portion1c of the board 1. The terminals 904 are directly connected to terminals907 disposed on the lower surface of the board 1 by soldering or thelike, and hence are not easily influenced by noise and the like.

The solid-state image sensing element 2 is sealed from the lower surfaceside with a resin member 903. With this resin member 903, thesolid-state image sensing element 2 is protected, and its mountingstrength with respect to the board 1 increases.

The opening portion 1c of the board 1 is covered with a glass member 50.The glass member 50 is disposed between the optical member G4 and theboard 1. The glass member 50 protects the image sensing surface 905 ofthe solid-state image sensing element 2.

In this embodiment, the glass member 50 for protecting the image sensingsurface 905 is disposed between the board 1 and the optical member G4.However, as shown in FIG. 10, a glass member 902 for protecting theimage sensing surface 905 of the solid-state image sensing element 2 maybe fitted in an opening portion 901 of the board 1. With thisarrangement, the glass member 902 does not protrude from the uppersurface of the board 1 so that an increase in the size of the board 1near the solid-state image sensing element 2 along the direction ofthickness can be suppressed. Consequently, the overall thickness of theapparatus can be decreased.

As shown in FIG. 11, instead of using the glass member 50, a portion ofthe optical member G4 may be fitted in the opening portion 901 of theboard 1 so that the optical member G4 can also serve as a glass memberfor protecting the image sensing surface 905 of the solid-state imagesensing element 2. In addition, the optical member G4 can be easilypositioned to the solid-state image sensing element 2.

Furthermore, this embodiment uses the solid-state image sensing element2 having the terminals 904 formed on its image sensing surface side.However, the embodiment may use an assembly obtained by mounting thesolid-state image sensing element 2 on a board such as a ceramic boardin advance. This assembly has electrodes to be connected to theterminals 904 of the solid-state image sensing element 2, and theseelectrodes can be directly connected to the electrodes on the lowersurface of the board 1.

As shown in FIG. 1, a plurality of circuit elements 45a and 45b aremounted on the board 1 in addition to the above parts constituting thephotographing optical system. The circuit elements 45a include elementsconstituting drive circuits for the actuators for the moving bases 3 and4 on which the optical members G2 and G3 are mounted, the actuator forthe moving base 3, and the respective positions sensors. The circuitelements 45b include elements constituting a drive circuit for thesolid-state image sensing element 2 and a video signal processingcircuit.

The board 1 has connectors 48 for connecting the circuit elements 45aand 45b to external circuits.

The shield case 49 is mounted on the board 1 to shield the parts mountedon the board 1 against magnetism and external light, suppress innersurface reflection, and prevent entrance of external dust. The shieldcase 49 is made of an iron plate whose inner surface is painted inblack.

A procedure for assembling the optical apparatus of this embodiment willbe described next.

In the first step, parts to be fixed are disposed on the board 1. Theparts to be fixed include the solid-state image sensing element 2, theoptical members G1 and G4, the coils 17 and 18 and the yokes 19 and 20which constitute the actuators for the optical members G2 and G3, therail portions 13, 14, 15, and 16, the position sensors 21 and 22, thecoils 38 and 42 and the yokes 39 and 43 of the stop unit 30, theposition sensors 40 and 44, and the circuit elements 45a and 45b.

The solid-state image sensing element 2 is fixed to the lower surface ofthe board 1 with a solder, an adhesive, or the like, and the terminals904 of the solid-state image sensing element 2 are electricallyconnected to the terminals 907 of the board 1.

The glass member 50 is mounted on the board 1 to cover the openingportion 1a, and the optical member G4 is fixed to the upper surface ofthe board 1. The optical member G4 is fixed to the board 1 with anadhesive or the like.

After the optical member G4 is mounted, the shafts G1a of the opticalmember G1 are fitted in the corresponding opening portions 1b. As aresult, the optical member G1 is positioned on the board 1.

Subsequently, other parts to be fixed are sequentially positioned andfixed to the board 1 with a solder, an adhesive, or the like. The coils17 and 18, the yokes 19 and 20, the position sensors 21 and 22, thecoils 38 and 42, the yokes 39 and 43, the position sensors 40 and 44,and the circuit elements 45a and 45b are connected to a wiring patternformed on the board 1.

Upon completion of the first step, mounting of the parts on the board 1and electrical connection of the coils, the position sensors, and thelike for drive control on movable members such as the aperture blades 31and 32 of the stop unit 30, the moving bases 3 and 4 on which theoptical members G2 and G3 are mounted, and the like are completed. Asdescribed above, since the parts to be fixed, including the solid-stateimage sensing element 2, which need to be electrically connected to theboard 1, are electrically connected to the board 1 with a solder or thelike without the mediacy of lead wires and a flexible printed board, theassembly step required for electric wiring can be omitted, resulting ina reduction in cost.

The second step is then executed. In the second step, the apertureblades 31 and 32 as movable members are mounted on the board 1. Morespecifically, the shaft 33 of the aperture blade 31 is inserted into thehole 37 in the board 1. Similarly, the shaft 34 of the aperture blade 32is inserted into the hole in the board 1.

The third step is executed. In the third step, the optical members G2and G3 constituting the photographing optical system and the movablemembers constituting the actuators for the optical members are mounted.The moving bases 3 and 4 are mounted on the rail portions 13, . . . , 16through the balls 46 and 47. The optical members G2 and G3 arepositioned on the moving bases 3 and 4.

The fourth step is executed. In the fourth step, the shield case 49 ismounted. The shield case 49 is placed on the board 1 to cover its uppersurface, and is fixed by soldering corresponding portions to groundpatterns on the board 1.

Upon completion of the fourth step, all the parts are mounted on theboard 1.

As described above, the assembly process can be simplified without usingany complicated, expensive part called a housing for holding an opticalsystem such as lenses in the prior art. A low-cost photographing opticalsystem can therefore be provided.

In addition, since the above members and parts are arranged on the flatboard 1, the positions and postures of the respective parts can beeasily determined such that an increase in the dimension of the board 1in the direction of thickness is minimized. Consequently, a low-profileoptical apparatus can be easily obtained.

The aperture blades 31 and 32 of the stop unit 30 rotate on a planeparallel to the board 1, and the yokes 39 and 43 are fitted in therecess portions formed in the board 1. With this arrangement, anincrease in the size of the board 1 in the direction of thickness due tothe aperture blades 31 and 32 of the stop unit 30 and the yokes 39 and43 can be suppressed to realize a lower-profile optical apparatus.

Furthermore, since the respective optical members, the regulation unitsfor the optical members, the stop unit 30, and the respective positionsensors are arranged on the board 1 on which the solid-state imagesensing element 2 is mounted, the position precision of each part can beimproved. Since the position sensors 21 and 22 for the optical membersG2 and G3 are accurately positioned on the moving bases 3 and 4, inparticular, the detection amounts from the position sensors 21 and 22become accurate values, and drive control on the optical members G2 andG3 can be accurately performed. As a result, deterioration in imagequality such as blurring and swinging of photographed images caused byinaccurate positioning of the position sensors 21 and 22, can beprevented.

In addition, when the shafts 33 and 34 of the aperture blades 31 and 32are respectively inserted into the holes 37 and 41 in the board 1, theaperture blades 31 and 32 can be positioned such that the apertureregulated by the aperture blades 31 and 32 coincides with the opticalaxis K. Therefore, the stop unit 30 can be positioned with respect tothe optical axis K with a simple procedure and high precision.

This embodiment exemplifies the photographing optical system constitutedby the optical members G1, G2, G3, and G4. In a photographing opticalsystem constituted by a lens group based on a refraction optical systemas in the prior art, or a photographing optical system additionallyhaving a lens group based on a refraction optical system, it is possibleto dispose these optical systems on a substrate or a moving base to bemovable.

The electrical arrangement of this embodiment will be described nextwith reference to FIG. 12. FIG. 12 is a block diagram showing thearrangement of the optical apparatus in FIG. 1.

As shown in FIG. 12, the optical apparatus has a photographing opticalsystem 601. The photographing optical system 601 includes a stop unitG12 (the stop unit 30 in FIG. 1) for regulating the amount of incidentlight, the optical member G2 which changes its position to change theimage magnification, the optical member G3 which changes its position toperform focus adjustment, and the optical member G4 whose position isfixed and on which an optical filter for removing unnecessaryhigh-frequency components and infrared rays contained in an object imageis formed.

Light emerging from the optical member G4 is incident on the solid-stateimage sensing element 2. The incident light is then converted into anelectrical signal by the solid-state image sensing element 2. Thesolid-state image sensing element 2 is driven by an image sensingelement drive circuit 604. The image sensing element drive circuit 604amplifies a timing signal generated by a clock circuit 603 and drivesthe solid-state image sensing element 2 by using the amplified signal.The timing at which the clock circuit 603 generates a timing signal iscontrolled by a CPU 616.

The electrical signal output from the solid-state image sensing element2 is supplied to a front end processing circuit 605. The front endprocessing circuit 605 amplifies the electrical signal from thesolid-state image sensing element 2 and performs a CDS process and thelike. The signal from the front end processing circuit 605 is convertedinto a digital signal by an A/D converter 606. This digital signal issupplied to a process circuit 607. The process circuit 607 variouslyprocesses the digital signal to form a video signal.

The video signal from the process circuit 607 is supplied to a displayunit 609 through a D/A converter 608, to an analog output 611 through aD/A converter 610, to a memory 612, to a digital output 613, to anin-focus information detection circuit 614, and to a luminanceinformation detection circuit 615.

The display unit 609 is constituted by an LCD for displaying an imagebased on the video signal. The analog output 611 is, for example, ananalog signal output terminal for outputting a signal to a TV monitor.The memory 612 records the video signal. The digital output 613 is, forexample, a terminal for outputting a signal to an external recordingmedium.

The in-focus information detection circuit 614 detects the in-focusstate of the object on the basis of the video signal from the processcircuit 607. The detection result is supplied to the CPU 616.

The luminance information detection circuit 615 detects the brightnessinformation of the object on the basis of the video signal from theprocess circuit 607. The detection result is supplied to the CPU 616.

The optical member G2 is moved in a predetermined direction by anactuator 617. As shown in FIG. 1, this actuator 617 is constituted bythe moving base 3, the permanent magnet 5, the coil 17, and the yoke 19.Drive control on the actuator 617 is performed by a control signal froman actuator control circuit 619. This control signal is amplified by adrive circuit 620 and supplied to the actuator 617. The position of theoptical member G2 is detected by a position detector 618. The positiondetector 618 is constituted by the position sensor 21 in FIG. 1. Thesignal from the position detector 618 is amplified by an amplifier 621and supplied to the CPU 616 through an A/D converter 622.

The optical member G3 is moved by an actuator 623 in a predetermineddirection. As shown in FIG. 1, this actuator 623 is constituted by themoving base 4, the permanent magnet 6, the coil 18, and the yoke 20.Drive control on the actuator 623 is performed by a control signal froman actuator control circuit 625. This control signal is amplified by adrive circuit 626 and supplied to the actuator 623. The position of theoptical member G3 is detected by a position detector 624. The positiondetector 624 is constituted by the position sensor 22 in FIG. 1. Thesignal from the position detector 624 is amplified by an amplifier 627and supplied to the CPU 616 through an A/D converter 628.

The stop unit G12 is moved by an actuator 629 to set a predeterminedaperture. As shown in FIG. 1, the actuator 629 is constituted by theaperture blades 31 and 32, the permanent magnets 35 and 36, the coils 38and 42, and the yokes 39 and 43. Drive control on the actuator 629 isperformed by a control signal from an actuator control circuit 631. Thiscontrol signal is amplified by a drive circuit 632 and supplied to theactuator 629. The aperture of the stop unit G12, i.e., the rotationalpositions of the aperture blades 31 and 32, are detected by a positiondetector 630. The position detector 630 is constituted by the positionsensors 40 and 44 in FIG. 1. Signals from the position detector 630 areamplified by an amplifier 633 and supplied to the CPU 616 through an A/Dconverter 634.

The CPU 616 controls the drive circuits 620 and 630 on the basis ofdetection results from the detectors 618, 624, and 630, a detectionresult from the in-focus information detection circuit 614, and adetection result from the luminance information detection circuit 615.

An operation designation signal from an operation unit 635 is suppliedto the CPU 616. The operation unit 635 generates an operationdesignation signal corresponding to an operation performed by aphotographer.

This circuit arrangement can be divided into the photographing opticalsystem 601, an actuator drive circuit 636, and a video signal processingcircuit 637 for processing an electrical signal from the solid-stateimage sensing element 2. The actuator drive circuit 636 includes theactuator control circuits 619, 625, and 631. The actuator drive circuit636 is arranged in the circuit element 45a in FIG. 1. The video signalprocessing circuit 637 is arranged in the circuit element 45b togetherwith the image sensing element drive circuit 604 and the clock circuit603.

Although the CPU 616, the in-focus information detection circuit 614,and the luminance information detection circuit 615 can be mounted onthe board 1, their mounting positions are not specifically limited.

The operation of the optical apparatus will be described next.

When the photographer operates the operation unit 635, an instruction tostart a photographing operation is input to the CPU 616. Upon receptionof this instruction, the CPU 616 turns on the power supply for eachcircuit, and instructs the clock circuit 603 to output a timing signalfor the solid-state image sensing element 2. The timing signal outputfrom the clock circuit 603 is amplified into a signal capable of drivingthe solid-state image sensing element 2 by the image sensing elementdrive circuit 604. Light incident on the solid-state image sensingelement 2 is converted into an electrical signal by this drive signal.This electrical signal is supplied to the front end processing circuit605. The front end processing circuit 605 performs processes such as aCDS process, a nonlinear process, and signal amplification for theelectrical signal from the solid-state image sensing element 2. Theoutput signal from the front end processing circuit 605 is convertedinto a digital signal by the A/D converter 606. The digital signal issupplied to the process circuit 607. The process circuit 607 performsvarious processes for visualizing the digital signal from the A/Dconverter 606, e.g., primary color separation and white balanceadjustment, gamma correction, aperture correction, and generation ofluminance and color difference signals. This video signal is convertedinto an analog signal by the D/A converter 608. An image represented bythe analog signal is displayed on the display unit 609. The video signalis recorded as a digital signal or output to an external equipment, asneeded.

The operation of the photographing optical system 601 will be describednext.

In general, focusing is automatically performed. Upon reception of avideo signal from the process circuit 607, the in-focus informationdetection circuit 614 detects the amount of high-frequency components(to be referred to as in-focus information hereinafter) of the inputvideo signal. As shown in FIG. 13, the in-focus information exhibits themaximum level when the photographing optical system 601 is in thein-focus state with respect to an object, and exhibits lower levels asthe photographing optical system 601 is defocused.

The CPU 616 detects a change in in-focus information while moving theoptical member G3, and controls the actuator control circuit 625 to movethe optical member G3 to the position where the in-focus informationexhibits the maximum level. The CPU 616 outputs a focus lens movingsignal to make the actual lens position follow a target lens positioncalculated from the in-focus information. Position information detectedby the position detector 624 is amplified by the amplifier 627 anddigitalized by the A/D converter 628. The resultant data is input to theCPU 616. The CPU 616 then calculates the actual lens position of theoptical member G3.

The actuator control circuit 625 generates an actuator control signal onthe basis of the focus lens moving signal. The actuator control signalis amplified into a signal capable of driving the actuator 623 by thedrive circuit 626 to drive the actuator 623. As the actuator 623 isdriven, the optical member G3 is moved to perform focusing.

Zooming is performed when the photographer operates the operation unit635. The CPU 616 calculates the target position of the optical member G2in accordance with an instruction input from the operation unit 635. Thecurrent lens position of the optical member G2 is detected by theposition detector 618. The output signal from the position detector 618is amplified by the amplifier 621 and input to the A/D converter 622.The output signal from the position detector 618, which is digitalizedby the A/D converter 622, is input to the CPU 616 to calculate the lensposition information of the optical member G2. The CPU 616 outputs amoving signal for the optical member to make the actual lens positionfollow the target lens position. The actuator control circuit 619generates an actuator control signal on the basis of the moving signalfor the optical member G2. The actuator control signal is amplified intoa signal capable of driving the actuator by the drive circuit 620 todrive the actuator 617. As the actuator 617 is driven, the opticalmember G2 is moved to perform zooming.

As in this embodiment, in the inner focus zoom lens, in order to performzooming while an object is in focus, the positions of the opticalmembers G2 and G3 must move on a predetermined curve (zoom trackingcurve). FIG. 14 shows zoom tracking curves. Referring to FIG. 14, "0.6m", "1.2 m", and "1.0 m" indicate object distances.

The current object distance is calculated on the basis of the positioninformation of the optical member G2, obtained by the position detector618, and the position information of the optical member G3, obtained bythe position detector 624. While a zooming operation is performed, thetarget position of the optical member G3 is calculated on the basis ofthe tracking curve corresponding to the current object distance. Similarto the optical member G2, the current lens position of the opticalmember G3 is detected by the position detector 624. The output signalfrom the position detector 624 is amplified by the amplifier 627 andinput to the A/D converter 628. The output signal from the positiondetector 624, which is digitalized by the A/D converter 628, is input tothe CPU 616 to calculate the lens position information of the opticalmember G3. The CPU 616 outputs a focus lens moving signal to make theactual lens position follow the target lens position. The actuatorcontrol circuit 625 generates an actuator control signal on the basis ofthe focus lens moving signal. The actuator control signal is amplifiedinto a signal capable of driving the actuator by the drive circuit 626to drive the actuator 623, thereby moving the optical member G3. Evenwhile zooming is performed, therefore, an object image is formed on thesolid-state image sensing element 2 without any image blur.

In performing exposure amount adjustment, the actuator 629 controls thestop unit G12 to change the aperture with respect to the photographingoptical system 601. Generally, this exposure amount adjustment isautomatically performed. A video signal from the process circuit 607 isinput to the luminance information detection circuit 615. The luminanceinformation detection circuit 615 detects the brightness (to be referredto as luminance information hereinafter) of the object image from theinput video signal. The current position of the stop unit G12 isdetected by the position detector 630. The output signal from theposition detector 630 is amplified by the amplifier 633 and input to theA/D converter 634. The output signal from the position detector 630,which is digitalized by the A/D converter 634, is input to the CPU 616to obtain the stop position information of the stop unit G12. The CPU616 calculates a proper exposure amount on the basis of the inputluminance information of the object image, and also calculates a targetstop position from the proper exposure amount and the current stopposition information. The CPU 616 then outputs a stop moving signal tomake the actual stop position follow the target stop position. Theactuator control circuit 631 generates an actuator control signal on thebasis of the stop moving signal. The actuator control signal isamplified into a signal capable of driving the actuator 629 by the drivecircuit 632 to drive the actuator 629. As the actuator 629 is driven,the stop unit G12 is moved to perform luminous amount adjustment.

The arrangement of the board 1 and a manufacturing method therefor willbe described next with reference to the accompanying drawings. FIG. 15is a longitudinal sectional view showing the arrangement of the board ofthe optical apparatus in FIG. 1. FIG. 16 is an exploded perspective viewpartly showing a process in the method of manufacturing the board of theoptical apparatus in FIG. 1.

As shown in FIG. 15, the board 1 comprises a ceramic base 801, ironbases 801a, and an aluminum base 801b. A ceramic material with excellentdimensional stability and heat dissipation property is used for theceramic base 801. The ceramic base 801 is a base forming the frame ofthe board 1. Iron with a high permeability is used for the iron bases801a. The iron bases 801a constitutes yokes (corresponding to the yokes19 and 20 in FIG. 1 and the yokes 39 and 44 in FIG. 2) partlyconstituting an actuator. The aluminum base 801b constitutes an imagesensing drive circuit or a video signal processing circuit. Aluminumwith a high heat conductivity is used for this base. Materials for thesebases 801, 801a, and 801b are not limited those described above. Forexample, a material with a high permeability, e.g., electromagneticsoft-iron or Permalloy, may be used for the iron bases 801a. A materialwith a high heat conductivity, e.g., copper, may be used for thealuminum base 801b. The bases 801, 801a, and 801b each have aninsulating layer 801c formed on its upper surface.

A method of manufacturing the board 1 will be described next withreference to FIG. 16.

Referring to FIG. 16, the ceramic base 801 having holes in portionscorresponding to the iron bases 801a and the aluminum base 801b, theiron bases 801a, and the aluminum base 801b are prepared.

The iron bases 801a and the aluminum base 801b are respectively fittedin the holes in the ceramic base 801. The iron bases 801a and thealuminum base 801b are fixed to the ceramic base 801 with an adhesive toform one base member.

Copper foils coated with a resin are stacked on the base member. As aresult, the insulating layers 801c are formed on the surfaces of theceramic base 801, the iron bases 801a, and the aluminum base 801b, asshown in FIG. 15. Instead of using this method, a method of coating abase member with a resin for forming insulating layers, and stackingcopper foils on the resin may be used as a method of forming theinsulating layers 801c. However, the former method is better because itallows a continuous process.

After the insulating layers 801c are formed, surface treatments aresequentially executed, e.g., etching the copper foils to form wiringpatterns, coating of a solder resist, solder plating on the exposedcopper foil surfaces, and a treatment using a solder leveler.

Subsequently, the solid-state image sensing element 2, the coils 17, 18,38, and 42, the circuit elements 45a and 45b, and the position sensors21 and 22 are electrically connected to the wiring patterns formed onthe board 1 with a solder or the like. The coils 17, 18, 38, and 42 andthe rail portions 13, 14, 15, and 16 are fixed to the board 1 with anadhesive.

As described above, one member is not used as the base member of theboard 1, but materials having properties suitable for characteristicsrequired by parts to be mounted on the board 1 are used for the basemember. More specifically, a ceramic base member with excellentdimensional stability including high flatness is used as the frame ofthe board, iron base members with a high permeability are used for theportions where the actuators are formed, and an aluminum or copper basemember is used for the portion where the image sensing element drivecircuit or video signal processing circuit requiring heat dissipation ofthe electronic parts are mounted. In this manner, optimal materials areselected for the respective portions on the board 1 to manufacture aboard which can make use of the merits of the respective base members.This structure is especially effective for heat dissipation ofelectronic parts, and hence board deformation caused by heat generatedby the electronic parts can be prevented. Consequently, a relativepositional offset between each optical member and the solid-state imagesensing element 2, tilting of each optical member, and the like due todeformation of the board 1 can be suppressed. Deterioration inphotographed images caused by deformation of the board 1 can thereforebe prevented.

In this embodiment, sheet-like coils are used, and these coils are fixedon the board 1 with an adhesive. However, similar to the patterns on theboard 1, coils can be formed by etching the copper foils. In this case,although the number of turns of each coil is limited, steps such as thestep of fixing the sheet coils can be omitted because the coils can beformed in the same manner as the wiring patterns. In addition,positioning of the sheet coils on the board 1 need not be performed.

A case wherein one member is used as the base member of a board will bedescribed next with reference to FIG. 17. FIG. 17 is a perspective viewshowing another board used for the optical apparatus in FIG. 1.

A board 802 is made of a metal board having a wiring pattern formed on ametal plate through an insulating layer. The material used for the metalboard is iron having a high permeability, or aluminum or copper having agood heat dissipation property, or the like. Since the insulating layerand the wiring patterns are formed in the same manner as describedabove, a description thereof will be omitted.

After the board 802 is prepared, the solid-state image sensing element 2is electrically connected to the wiring pattern on the lower surface ofthe board 802, whereas the coils 17, 18, 38, and 42, the circuitelements 45a and 45b, and the position sensors 12 and 22 areelectrically connected to the wiring patterns on the upper surface ofthe board 802. These wiring patterns are formed on the board 802 with asolder or the like. The coils 17, 18, 38, and 42 and the rail portions13, . . . , 16 are fixed to the board 802 with an adhesive. According tothis method, since a board can be formed by using one metal plate as abase, a board with high flatness can be formed at a low cost. Inaddition to these effect, the following effects (a) and (b) can beobtained in accordance with a material for a metal portion of the board.

(a) A material having a high permeability, e.g., iron:

When an optical system is to be driven by an electromagnetic drivescheme, since a portion of the board serves as a yoke, a yoke as a partneed not be used. A reduction in cost can therefore be attained.

(b) A material having good heat dissipation property, e.g., aluminum:

Since heat generated around the image sensing element drive circuit, thevideo signal processing circuit, and the coils of the actuators can beefficiently dissipated, deformation such as warpage of the board can beprevented.

A method of effectively preventing deformation of the board due to heatgenerated by electronic parts thereon and mechanical deformation of theboard will be described next with reference to FIGS. 18 to 20. FIG. 18is a perspective view showing another board used for the opticalapparatus in FIG. 1. FIG. 19 is a perspective view showing still anotherboard used for the optical apparatus in FIG. 1. FIG. 20 shows themounted state of the board in FIG. 19.

This method includes a method of forming notched portions 809 around anelectronic part 812 such as a CPU requiring heat dissipation, as shownin FIG. 18, and a method of forming V-shaped grooves 810 around theentire optical system for which the flatness of the board must bemaintained, as shown in FIG. 19.

Methods of mounting the board 1 on an equipment on the basis of theabove methods will be described with reference to FIGS. 18 to 20.

As shown in FIGS. 18 and 19, mounting holes 811 are formed in the fourcorners of the board 1 in the respective methods. A mounting area for anelectronic part such as a CPU which generates a large quantity of heaton the board 1 is separated with the notched portions 809 or theV-shaped grooves 810.

These methods of mounting the board 1 will be described with referenceto the board 1 shown in FIG. 19.

As shown in FIG. 20, the board 1 is fixed to a board mounting portion814 in the equipment with screws 813 extending through the mountingholes 811.

When the board mounting portion 814 is deformed by a force outside theequipment or owing to a process precision, an external force acts on theboard 1. However, only the V-shaped grooves 810 are deformed by thisexternal force, and the remaining portion of the board 1 maintains itsflatness.

The board 1 having the notched portions 809 in FIG. 18 also exhibits thesame effect as described above.

A structure for absorbing thermal deformation of the board 1 in FIG. 18will be describe next.

More specifically, when the electronic part 812 is placed in an areabetween the notched portion 809 and the edge portion, thermaldeformation such as warpage of a portion of the board 1 around theelectronic part 812, caused by heat generated by the electronic part812, is absorbed by the notched portion 809 as in the case wherein theabove mechanical deformation is absorbed by the V-shaped groove 810. Anarea extending inward from the notched portion 809 can maintain itsflatness.

Still another board arrangement will be described next with reference toFIGS. 21 and 22. FIG. 21 is a perspective view showing still anotherboard used for the optical apparatus in FIG. 21. FIG. 22 is alongitudinal sectional view showing the board in FIG. 21.

Referring to FIGS. 21 and 22, a board 821 is constituted by twosub-boards 821a and 821b having wiring patterns formed on metal platesthrough insulating layers.

An iron base having a high permeability is used for the sub-board 821aon which an actuator is formed, whereas an aluminum base or the likehaving a high heat conductivity is used for the sub-board 821b on whichan image sensing drive or a video signal processing circuit is formed.Insulating layers 821c and 821d are respectively formed on the uppersurfaces of the sub-boards 821a and 821b. An coaxially extending openingportion 829 is formed in the sub-board 821a and the insulating layer821c. An coaxially extending opening portion 830 is formed in thesub-board 821b an the insulating layer 821d. The solid-state imagesensing element 2 is inserted into the opening portion 830. Thesolid-state image sensing element 2 is mounted on the lower surface ofthe sub-board 821b. Object light is incident on the solid-state imagesensing element 2 through the opening portion 830.

A method of manufacturing the board 821 will be described next.

First of all, an iron base as the sub-board 821a on which an actuator isformed, and a copper or aluminum base as the sub-board 821b areprepared.

Copper foils are coated with a resin and are respectively stacked on thebase members to form the insulating layers 821c and 821d on the uppersurfaces of the sub-boards 821a and 821b.

After the insulating layers 821c and 821d are formed, the foils areetched to form a wiring pattern for an actuator circuit on the sub-board821a, and a wiring pattern for an image sensing element drive circuit orvideo signal processing circuit on the sub-board 821b.

Subsequently, surface treatments are sequentially performed, e.g.,coating of a solder resist, solder plating for the exposed copper foilsurfaces, and a treatment using a solder leveler.

The sub-boards 821a and 821b are stacked through an insulating adhesive.

With the use of this board 821, the same effects as those of the boardin FIG. 15 can be obtained. In addition, the sub-board 821a on which theactuator drive system serving as a noise source, i.e., the circuitelement 45a and the actuator, is formed, and the sub-board 821b on whichthe circuit element 45b for the image sensing driving circuit or videosignal processing circuit susceptible to noise and the image sensingelement drive circuit or video signal processing circuit are formed canbe formed on different layers on the board 821 so that the influences ofnoise in the board 821 can be minimized. Note that the above videosignal processing circuit is equivalent to the video signal processingcircuit 637 in FIG. 12, but its inner arrangement is not limited.

In manufacturing the board 821, two bases can be independentlymanufactured by a conventional forming method, unlike the case of theboard 1 in FIG. 16 in which bases are fitted in holes formed in a basein advance to form one base. The manufacturing process can therefore besimplified, and a reduction in manufacturing cost can be attained.

(Second Embodiment)

The second embodiment of the present invention will be described nextwith reference to FIGS. 23 to 26. FIG. 23 is an exploded perspectiveview showing the arrangement of an optical apparatus according to thesecond embodiment of the present invention. FIG. 24 is a longitudinalsectional view showing the arrangement of a drive control unit for thesecond optical member of the optical apparatus in FIG. 23. FIG. 25 is alongitudinal sectional view showing the arrangement of a drive controlunit for the aperture blades of the optical apparatus in FIG. 23. FIG.26 is a sectional view taken along a line C--C in FIG. 25.

This embodiment is an optical apparatus having a zoom lens mechanismusing a refraction optical system.

As shown in FIG. 23, the optical apparatus includes a board 1 on which asolid-state image sensing element 2 is mounted. Note that the board 1 isconstituted by a plurality of base members consisting of differentmaterials, similar to the arrangement of the board in the firstembodiment, and a description thereof will be omitted.

First to fourth lens groups 60 to 63 are mounted on the board 1.

The first lens group 60 is fixed to the board 1 with an adhesive. Thesecond lens group 61 is constituted by a lens group for performing azooming operation. This lens group is mounted on the board 1 to bemovable along an optical axis 64 within a predetermined range. The thirdlens group 62 is fixed to the board 1 with an adhesive or the like,similar to the first lens group 60. The fourth lens group 63 isconstituted by a lens group for performing a focusing operation. Thislens group is mounted on the board 1 to be movable along the opticalaxis 64 within a predetermined range. The optical axis 64 is set to beparallel to the upper surface of the board 1. That is, since the movingdirections of the second and fourth lens groups 61 and 63 are set to beparallel to the upper surface of the board 1, even if the movable rangesare long, a zoom mechanism can be realized without increasing the sizein a direction perpendicular to the upper surface of the board 1.

An optical member 65 such as a triangular prism is disposed behind thefourth lens group 63. The optical member 65 serves to bend the opticalaxis in a direction perpendicular to the board 1 so as to form an objectimage on the image sensing element 2. Note that the structure formounting the solid-state image sensing element 2 on the board 1 is thesame as that in the first embodiment, and a description thereof will beomitted.

Aperture blades 66 are disposed between the second and third lens groups61 and 62. Each aperture blade 66 is driven in a direction perpendicularto the optical axis 64 to change aperture. With this change in aperture,the amount of object image light is adjusted.

The second lens group 61, the fourth lens group 63, and the apertureblades 66 are respectively driven and controlled by drive control units67, 68, and 69. Each of the drive control units 67, 68, and 69 isconstituted by an actuator, a position sensor, and the like.

Electronic parts 71 and connector portions 70 for connection withexternal circuits are mounted on the board 1. The electronic parts 71include circuit elements for controlling the drive control units 67, 68,and 69, a circuit element for driving the solid-state image sensingelement 2, a circuit element for processing a signal from thesolid-state image sensing element 2, and the like.

The board 1 is stored in a box-like shield case constituted by a pair ofcase portions 72 and 73. For example, the case portions 72 and 73 areconstituted by iron plates whose inner surfaces are painted in black toblock electromagnetism and external light, suppress inner surfacereflection, and prevent entrance of external dust. The case portions 72and 73 are fixed to each other by soldering their corresponding portionsto ground patterns on the board 1.

The arrangement of the drive control unit 67 of the second lens group 61will be described next with reference to FIG. 24.

As shown in FIG. 24, the second lens group 61 is held by an opticalholding member 80. The optical holding member 80 is constituted by aframe member for supporting the second lens group 61, and a pair ofplate-like support portions extending from the frame portion to beparallel to the board 1 in a direction perpendicular to the optical axis64. A V-shaped groove 81 extending along the optical axis 64 is formedin the surface, of one support portion, which opposes the board 1, and agroove 82 having a recess-like cross-section and extending along theoptical axis 64 is formed in the surface, of the other support portion,which opposes the board 1. In addition, a magnetic scale 87 extendingalong the optical axis 64 is mounted on the optical holding member 80. Apermanent magnet 83 is mounted on the surface, of each support portion,which opposes the board 1.

An opening portion 1d is formed in the board 1 to prevent interferencebetween the board 1 and the optical holding member 80.

A pair of rail portions 86 in which V-shaped grooves extending along theoptical axis 64 are formed, and a position sensor 88 are mounted on theboard 1.

The V-shaped groove of one rail portion 86 opposes the V-shaped groove81 of the optical holding member 80. The V-shaped groove of the otherrail portion 86 opposes the groove 82 of the other rail portion 86.Balls 85 are respectively interposed between the V-shaped groove of onerail portion 86 and the V-shaped groove 81 and between the V-shapedgroove of the other rail portion 86 and the groove 82.

The position sensor 88 is constituted by a sensor for detecting amagnetic force from the magnetic scale 87.

The optical holding member 80, and the permanent magnet 83 and themagnetic scale 87 which are mounted on the optical holding member 80constitute the drive control unit 67, together with coils 84, yokes 89,the rail portions 86, the position sensor 88, and the balls 85 which aremounted on the board 1.

The basic driving principle of the drive control unit 67 is the same asthat in the first embodiment, and a description thereof will be omitted.

The arrangement of the drive control units 69 for the aperture blades 66will be described next with reference to FIGS. 25 and 26.

As shown in FIG. 25, each aperture blade 66 is constituted by acorresponding one of blades 91a and 91b which are movable in directions(indicated by the arrows in FIG. 25) perpendicular to the optical axis.The blades 91a and 91b respectively have V-shaped notches. The blades91a and 91b are disposed such that their notched portions overlap. Theseblades 91a and 91b cooperate to form an aperture 92. The opening area ofthe aperture 92 is determined by the moving amounts of the blades 91aand 91b.

As shown in FIG. 26, a V-shaped groove and a groove having a recess-likecross-section are formed in the surface, of the blade 91a, which opposesthe board 1. These grooves extend in a direction perpendicular to theoptical axis 64. In addition, a magnetic scale 97 extending along adirection perpendicular tot he optical axis 64 is mounted on thissurface. A permanent magnet 93 is mounted on the surface, of each of theblades 91a and 91b, which opposes the board 1.

A pair of coils 94 are mounted on the board 1. Each coil 94 is disposedon the board 1 to oppose a corresponding one of the permanent magnets93. A yoke 95 is disposed below each coil 94.

A pair of rail portions in which V-shaped grooves extending in adirection perpendicular to the optical axis 64 are formed, and aposition sensor 98 are mounted on the board 1.

One rail portion is disposed such that its V-shaped groove opposes theV-shaped groove of the blade 91a. The other rail portion is disposedsuch that its V-shaped portion opposes the groove, of the blade 91a,which has the recess-like cross-section. Balls 96 are respectivelyinterposed between the V-shaped groove of one rail portion and theV-shaped groove of the blade 91a and between the V-shaped groove of theother rail portion and the groove, of the blade 91a, which has therecess-like cross-section.

The position sensor 98 is constituted by a sensor for detecting amagnetic force from the magnetic scale 97.

The blades 91a and 91b, and the permanent magnets 93 and the magneticscales 97 which are mounted on the blades 91a and 91b constitute thedrive control units 69 for the aperture blades 66, together with thecoils 94, the yokes 95, the rail portions, the position sensor, and theballs which are mounted on the board 1.

When the aperture blades 66 are driven by the drive control units 69,since the blades 91a and 91b are much lighter than the permanent magnets93, the center of gravity of the movable portion constituted by thepermanent magnets 93 and the blades 91a and 91b is near the permanentmagnets 93, and a driving force from the actuator acts on the center ofgravity. The blades 91a and 91b can therefore be driven in a stablestate.

As described above, in the second embodiment, since the actuator portionand the board 1 are arranged so as not to overlap the optical system inthe direction of thickness, a thickness d of the optical holding member80 or the second lens group 61 as an optical system (in this case, thethickness d corresponds to the diameter of the optical holding member80) determines an overall thickness t of the optical apparatus. That is,the thickness of the optical apparatus can be decreased.

In addition, since the optical members, the mechanical members such asactuators and drive circuits therefor, and the electric members arearranged on the board 1 on which the solid-state image sensing element 2is mounted, a complicated, expensive part called a lens barrel forholding optical systems such as lenses as in the prior art need not beused, and the assembly process can be simplified, thereby providing alow-cost optical apparatus.

Since the mechanical members, the optical members, and the electricalmembers are arranged on the board 1 which extends two-dimensionally, thepositions and postures of the respective parts can be easily determinedsuch that an increase in the size of the board 1 in the direction ofthickness is minimized. A low-profile optical apparatus can therefore beprovided.

Furthermore, when the respective optical members for the solid-stateimage sensing element 2, the regulation units for the optical members,and the stop unit are arranged on the board, the position precision ofeach component can be improved.

When the actuators serving as noise sources are arranged on the uppersurface of the board 1, and the solid-state image sensing element 2 isarranged on the lower surface of the board 1, the influences of noise onthe solid-state image sensing element 2 can be reduced.

In each embodiment described above, one substrate is used. However, aplurality of divided substrates arranged on the same plane may be used.

As described above, the optical apparatus of the present invention hasthe board on which the photographing optical system and the solid-stateimaging sensing element are mounted. The movable optical membersincluded in the photographing optical system and capable of movingrelative to the solid-state imaging sensing element, and the positiondetection means for detecting the moving positions of the movableoptical members are mounted on the board. With this arrangement, anincrease in size of the board in the direction of thickness can besuppressed, and the movable optical members and the position detectionmeans can be accurately positioned on the board, thereby preventingdeterioration in image quality due to inaccurate relative positioningbetween the movable optical members included in the photographingoptical system and the position detection means, and attaining adecrease in the overall thickness of the apparatus.

Since the movable optical members are held by the holding means mountedon the board to be movable in a predetermined direction, the positionsof the movable optical members can be detected by detecting the movingpositions of the holding means.

Since at least a portion of the drive circuit for each positiondetection means is mounted on the board, the position detection meanscan be connected to the drive circuit through the board without usingany flexible board for wiring connection between the position detectionmeans and the drive circuit, thereby attaining a reduction in cost. Inaddition, the degree of freedom in terms of the position of the drivecircuit. For example, the drive circuit can be arranged at a positionwhere other circuits are free from the influences of noise.

Since at least a portion of the drive circuit for each positiondetection means is formed on the board, the position detection means canbe connected to the drive circuit through the board without using anyflexible board for wiring connection between the position detectionmeans and the drive circuit, thereby attaining a reduction in cost. Inaddition, the degree of freedom in terms of the position of the drivecircuit. For example, the drive circuit can be arranged at a positionwhere other circuits are free from the influences of noise.

Furthermore, the optical apparatus has the board on which thephotographing optical system and the solid-state imaging sensing elementare mounted. The movable optical members included in the photographingoptical system and capable of moving relative to the solid-state imagingsensing element, and at least some of the constituent members of theactuator for moving each movable optical member in a predetermineddirection are mounted on the board. With this arrangement, no housingfor storing and holding the photographing optical system is required,and the photographing optical system, the movable optical membersincluded in the system, at least some of the constituent members of theactuators, and the solid-state imaging sensing element can be positionedon the board tow-dimensionally. As a result, good assembly performance,a reduction in cost, and a decease in thickness can be achieved.

Since the constituent members of each actuator include the movablemember which moves in a predetermined direction while holding themovable optical member, the movable member also serves as a holdingmember for the movable optical member.

Since at least some of the parts constituting the drive circuits for theactuators are mounted on the board, the positions and postures of thephotographing optical system, the actuators, and the drive circuits canbe determined so as not to increase the size of the board in thedirection of thickness.

The movable member of each actuator is not electrically connected to theboard. For this reason, no wiring is required between the movablemembers and the board, and the mechanical load based on wiring can beeliminated.

Since each actuator drives the movable member by using anelectromagnetic force generated by the driving force generation means,the arrangement of the actuator can be simplified.

Each driving force generation means is constituted by the magnet mountedon the movable member and the coil and yoke mounted on the board. Forthis reason, the arrangement of the driving force generation means canbe simplified, and hence the arrangement of the actuator can be furthersimplified.

Since each yoke is constituted by a portion of the board, no new partconstituting the yoke needs to be prepared, and a reduction in cost canbe attained.

Furthermore, the optical apparatus has the board on which thephotographing optical system and the solid-state imaging sensing elementare mounted. The light amount adjustment means for adjusting the lightamount of an object image, and at least some of the constituent membersof the actuator for driving the light amount adjustment means aremounted on the board. With this arrangement, the photographing opticalsystem, the light amount adjustment means, at least some of theconstituent members of the actuator, and the solid-state imaging sensingelement can be positioned on the board two-dimensionally. As a result,good assembly performance, a reduction in cost, and a decease inthickness can be achieved.

As the light amount adjustment means, a means for performing lightamount adjustment in accordance with the size of an aperture formed bythe operations of a plurality of movable adjustment members can be used.

Since the constituent members of the actuator include the movable memberfor driving the movable adjustment member of the light amount adjustmentmeans while holding the member, the movable member can also serve as theholding member for the movable adjustment member.

Since at some of the parts constituting the drive circuit for theactuator are mounted on the board, the positions and postures of thephotographing optical system, the light amount adjustment means,actuators therefore, and drive circuits therefor can be determined so asnot to increase the size in the direction of thickness.

The movable member of each actuator is not electrically connected to theboard. For this reason, no wiring is required between the movablemembers and the board, and the mechanical load based on wiring can beeliminated.

Since each actuator drives the movable member by using anelectromagnetic force generated by the driving force generation means,the arrangement of the actuator can be simplified.

Each driving force generation means is constituted by the magnet mountedon the movable member and the coil and yoke mounted on the board. Forthis reason, the arrangement of the driving force generation means canbe simplified, and hence the arrangement of the actuator can be furthersimplified.

Since the actuator drives the movable adjustment member of the lightamount adjustment means by using an electromagnetic force generated bythe driving force generation means, the arrangement of the actuator canbe simplified.

The driving force generation means is constituted by the magnet mountedon the movable adjustment member of the light amount adjustment meansand the coil and yoke mounted on the board. For this reason, thearrangement of the driving force generation means can be simplified, andhence the arrangement of the actuator can be further simplified.

Since each yoke is constituted by a portion of the board, no new partconstituting the yoke needs to be prepared, and a reduction in cost canbe attained.

In addition, the light amount adjustment means for performing a lightamount adjusting operation to adjust the light amount of an objectimage, and the drive means for generating a driving force used by thelight amount adjustment means to perform a light amount adjustingoperation are arranged on a plane parallel to the board on which thephotographing optical system and the solid-state image sensing elementare mounted. With this arrangement, an increase in the size of the boardin the direction of thickness due to the light amount adjustment meansand the drive means can be minimized. That is, there is no chance thatthe light amount adjustment means and the drive means interfere with adecrease in the overall thickness of the apparatus.

An optical path portion extending in a direction perpendicular to theboard is included in the optical path formed by the photographingoptical system, and the light amount adjustment means is disposed toadjust the amount of light passing through the optical path portion.With this arrangement, the amount of light passing through the opticalpath portion extending in the direction perpendicular to the board canbe adjusted by the light amount adjustment means.

The light amount adjustment means includes the movable adjustment memberfor performing a light amount adjusting operation by adjusting the lightamount passage area of the optical path portion, and the movableadjustment member moves along a plane almost parallel to the board.Therefore, an increase in the size of the board in the direction ofthickness due to the movable adjustment member can be minimized.

The movable adjustment member has the shaft rotatably and verticallysupported on the board, and the movable adjustment member rotates aboutthe shaft. Therefore, the amount of light passing through the opticalpath portion extending in a direction perpendicular to the board can beadjusted without increasing the size of the board in the direction ofthickness.

Since some of the constituent elements of each drive means are mountedon the board, an increase in the size of the board in the direction ofthickness due to the drive means can be further suppressed.

The regulation portions for regulating the position of the light amountadjustment means are formed on the board on which the photographingoptical system, the solid-state image sensing element, and the lightamount adjustment means for performing a light amount adjustingoperation to adjust the light amount of an object image are mounted.With this arrangement, the position of the light amount adjustment meanswhich corresponds to the optical axis of the photographing opticalsystem can be determined by the position regulation portions in advance,and the light amount adjustment means can be positioned with respect tothe optical axis of the photographing optical system by a simpleoperation procedure with a high precision.

An optical path portion extending in a direction perpendicular to theboard is included in the optical path formed by the photographingoptical system, and the light amount adjustment means is positioned bythe regulation portions on the board to adjust the amount of lightpassing through the optical path portion. Therefore, positioning can beeasily performed with respect to the optical path portion formed by thephotographing optical system and extending in the directionperpendicular to the board.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

What is claimed is:
 1. A flat camera comprising,(a) a prism opticalsystem having plural optical members; (b) an image sensing device forsensing an image formed by said prism optical system, and for outputtingan image signal corresponding to the image; and (c) moving means formoving said optical members, and for adjusting the optical members topredetermined optical positions.
 2. A flat camera according to claim 1,wherein said moving means moves a first optical member for focusing. 3.A flat camera according to claim 2, further comprising a detectioncircuit for detecting an in-focus state of the first optical member byusing predetermined components of the image signal,wherein said movingmeans moves the first optical member on the basis of the in-focus statedetected by said detection circuit.
 4. A flat camera according to claim1, wherein said moving means moves a second optical member for zooming.5. A flat camera according to claim 4, further comprising a controlcircuit for compensating the position of the second optical member to apredetermined zooming position.
 6. A flat camera comprising,(a) a prismoptical system having plural optical members supported on one surface ofa board; and (b) an image sensor arranged to the other surface of theboard, for sensing a light which emerges from said prism optical systemvia opening formed on the board, and for changing the light to an imagesignal.
 7. A flat camera according to claim 6, further comprisingsupport means for supporting said optical members to be movable, anddrive means for driving said optical members, said support means anddrive means arranged on the one surface of the board.
 8. A flat cameraaccording to claim 7, further comprising a drive circuit for drivingsaid image sensor; a signal processing circuit for processing an imagesignal output from said image sensor; and a control circuit forcontrolling said driving means, said drive circuit, signal processingcircuit and control circuit arranged on the other surface of the board.9. A flat camera according to claim 8, wherein said optical members areprisms, and wherein said control circuit drives the prisms for focusingby said drive means.
 10. A flat camera according to claim 9, whereinsaid control circuit drives the prisms for zooming by said drive means.